Test apparatus having multiple head boards at one handler and its test method

ABSTRACT

A test apparatus includes one handler connected to a tester and one test board divided into two or more sites or two or more test boards. Since only the sites on the test board (or test boards) need be duplicated, rather than the loading lanes or sorters of the handler, the test apparatus can be conveniently compact. Further, while testing semiconductor devices on one site or one test board, semiconductor devices in another site or on another test board can be sorted according to the test result. This enables the reduction or elimination of tester idle time to optimize the efficiency of the test apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.11/092,067, filed on Mar. 28, 2005, now pending, which is a Divisionalof U.S. patent application Ser. No. 10/672,994, filed on Sep. 25, 2003,now U.S. Pat. No. 6,903,567, which claims priority from Korean PatentApplication No. 2002-58349, filed on Sep. 26, 2002, the contents ofwhich are herein incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to semiconductor device testing, and moreparticularly to a test apparatus and method involving two test boardsthat interact with one handler.

BACKGROUND OF THE INVENTION

After all processes are carried out, semiconductor devices are packagedand their functions are electrically tested by means of a tester andhandler. The tester, which includes a waveform generator, acurrent/voltage generator, and a current/voltage-measuring unit, teststhe electrical functions of semiconductor devices according to the testprogram. The handler is a kind of robot that automatically conducts theelectrical function test for each semiconductor “device under test”(DUT). The handler is an automated assembly to load/unload the DUTs fortesting and to sort the tested DUTs based on the test result. A teststation is a place where the tester conducts the electric function test,and a test head is a kind of a gate between the handler and the tester.

A test flow between a tester and a handler head is described below withreference to FIG. 1.

Referring to FIG. 1, a signal is transmitted between a handler head 100and a tester 120 through a communication interface 130. While chips aremoved from the chip tray to the handler head 110, the tester 120 is inan idle state ({circle around (1)}). When a chip is connected to asocket, the handler head 110 transmits a test-start signal to the tester120 ({circle around (2)}). The tester 120 tests the electronic functionof the chip in response to the test-start signal and transmits atest-end signal to the handler head 110 when the test ends ({circlearound (3)}). The handler head 110 sorts the tested chips into goodchips and defective chips ({circle around (4)}). At this time, thetester is again in the idle state. A reduction or elimination of thetester idle time is desirable because it would improve the efficiency ofthe test apparatus.

One example of a test apparatus that reduces tester idle time isdisclosed in Korean Patent Application No. 2000-56000, in which amulti-handler has two test points, two sorting means, and two loadinglanes, and a test signal is transmitted in a time-division manner toeach of the alternate paths of the multi-handler. A test apparatusaccording to the above patent includes two handlers, two stations, andtwo head boards. While one semiconductor device is tested at one handlerportion, another semiconductor device is sorted and a new semiconductordevice is loaded at another handler portion. Unfortunately, because somany of the handler components are duplicated, the test apparatus of theabove patent is still fairly large.

SUMMARY OF THE INVENTION

A test apparatus having a relatively small size and yet reduces testidle time, and its test method, are provided.

A first embodiment of the present invention provides a test apparatusfor testing a plurality of semiconductor devices loaded on one handlerconnected to a tester. The handler includes a test head that countscycles of a test-clock signal provided by the tester and responds byalternately generating an odd-number signal and an even-number signal,and a lateral head board divided into a first site and a second site onwhich the DUTs are loaded. The tester tests the DUTs loaded on the firstsite in response to the odd-number signal, and the tester tests the DUTSloaded on the second site in response to the even-number signal.

In a second embodiment, the handler includes a test head that countscycles of a test-clock signal provided by the tester and responds byalternately generating an odd-number signal and an even-number signal, afirst lateral head board on which the DUTs are loaded, and a secondlateral head board on which the DUTs are loaded. The tester tests theDUTs loaded on the first head board in response to the odd-numbersignal, and the tester tests the DUTs loaded on the second head board inresponse to the even-number signal.

In a third embodiment, the handler includes a test head on which fusesare selectively shorted by a voltage source to alternately generate afirst selection signal and a second selection signal, and a head boarddivided into first and second sites on which the DUTs are loaded. Thetester tests the DUTs loaded on the first site in response to the firstselection signal, and the tester tests the DUTs loaded on the secondsite in response to the second selection signal.

In a fourth embodiment, the handler includes a test head on which fusesselectively shorted by a voltage source alternately generate a firstselection signal and a second selection signal, a first head board onwhich the DUTs are loaded, and a second head board on which the DUTs areloaded. The DUTs loaded on the first head board are tested in responseto the first selection signal, and the tester tests the DUTs loaded onthe second head board in response to the second selection signal.

In a fifth embodiment, the invention provides a method of testing aplurality of semiconductor devices loaded on one handler connected to atester. The method includes loading the semiconductor devices on two ormore sites of the handler's head board, making the handler transmit atest-require signal to the tester, making the tester receive thetest-require signal and query the handler as to whether thesemiconductor devices are all loaded on a fullsite, making the handlercount cycles of a test clock signal from the tester to generate siteselection signals for selecting the site, testing the DUTs loaded on asite in response to the corresponding site selection signal, sorting thetested DUTs according to their test results, and selecting another sitein response to the site selection signal.

In a sixth embodiment, the method includes loading the semiconductordevices on two or more sites of the handler head board, making thehandler transmit a test-require signal to the tester, making the testerreceive the test-require signal and query the handler whether thesemiconductor devices are loaded on a fullsite, making the handlerselectively short embedded fuses to a voltage source to generate siteselection signals for selecting the sites, testing the DUTs loaded on asite in response to the corresponding site selection signal, and sortingthe tested DUTs according to their test results and selecting anothersite in response to the site selection signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a test flow between a conventional test and a handler.

FIG. 2 shows a handler according to a first embodiment of the presentinvention.

FIG. 3 shows a handler according to a second embodiment of the presentinvention.

FIG. 4 shows a handler according to a third embodiment of the presentinvention.

FIG. 5 shows a handler according to a fourth embodiment of the presentinvention.

FIG. 6 shows a flowchart of a test method between a tester and a handleraccording to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A handler according to a first embodiment of the present invention isnow described below with reference to FIG. 2.

Referring to FIG. 2, a handler 200 is connected to a tester to test aplurality of loaded semiconductor devices DUT. The handler 200 includesa test head 210 and a lateral handler head board 220. The test head 210has a counter 212 that counts cycles from a test clock signal TCLKprovided by the tester and responds by alternately generating anodd-number signal ODD and an even-number signal EVEN. A plurality ofDUTs are loaded onto the lateral handler head board 220, which isdivided along its width into: a first site 222 and a second site 224.The tester tests the DUTs loaded on the first site 222 in response tothe odd-number signal ODD, and the tester tests the DUTs loaded on thesecond site 224 in response to the even-number signal EVEN.

The present invention achieves the advantage of reducing or eliminatingtester idle time because the handler 200 sorts tested DUTs from, orloads new untested DUTS to, one of the sites on the lateral board whilethe tester tests DUTs on the other site. Thus, when the tester finishestesting DUTs on one site, it can immediately begin testing the newlyloaded DUTs on the other site without intervening idle time. Further,since a single handler loading to and sorting from two sites isconnected to the tester, the test apparatus can be conveniently compact.

Although the lateral board 220 is divided into two sites (i.e., thefirst and second sites 222 and 224) in the first embodiment, it may bedivided into three sites or more. Therefore, it will be understood thatthe test head 210 may divide the test clock signal TCLK into three ormore distinguishable timing signals.

A handler according to a second embodiment of the present invention isnow described with reference to FIG. 3.

Referring to FIG. 3, a handler 300 includes a test head 310, a firsttest board 320, and a second test board 330. The test head 310 isidentical with the test head 210 of FIG. 2, with a counter 312 thatcounts cycles of a test clock signal TCLK from the tester and respondsby alternately generating an odd-number signal ODD and an even-numbersignal EVEN. Unlike the sites 222 and 224 on the same lateral board 220of FIG. 2, the sites in this second embodiment are on two separate testboards 320 and 330. A plurality of DUTs are loaded onto each of the testboards 320 and 330. The first test board 320 tests DUTs in response tothe odd-number signal ODD, and the second test board 330 testssemiconductor devices in response to the even-number signal EVEN.

A handler according to a third embodiment of the present invention isnow described with reference to FIG. 4.

Referring to FIG. 4, a handler 400 includes a test head 410 and avertical board portion 420. The test head 410 has a fuse unit 412 whichselectively connects internal fuses to a voltage source VCC, generatingeither a first selection signal FS1 or a second selection signal FS2depending on whether an internal fuse is shorted. Like the lateralhandler head board 220 of FIG. 2, the vertical handler head board 420 isdivided into a first site 422 and a second site 424, but the verticalconfiguration of FIG. 4 allows the location of sites 422 and 424 onopposite surfaces of the handler head board. DUTs loaded on the firstsite 422 are tested in response to the first selection signal FS1, andDUTs loaded on the second site 424 are tested in response to the secondselection signal FS2.

Although the vertical board portion 420 is divided into two sites (i.e.,the first and second sites 422 and 424) in the third embodiment, it maybe divided into three sites or more. Therefore, the fuse unit may have aplurality of fuses to generate various selection signals and toselectively test semiconductor devices in a corresponding site.

A handler according to a fourth embodiment of the present invention isnow described with reference to FIG. 5.

Referring to FIG. 5, a handler 500 includes a test head 510, a firsttest board 520, and a second test board 530. The test head 510 has afuse unit 512. Similar to the test head 410 of FIG. 4, the test head 510generates a first selection signal FS1 or a second selection signal FS2depending on whether a fuse in the fuse unit 512 is shorted. DUTs loadedon the first test board 520 are tested in response to the firstselection signal FS1, and DUTs loaded on the second test board 530 aretested in response to the second selection signal FS2.

A test flow between a tester and a handler according to the presentinvention is now described with reference to FIG. 6.

Referring to FIG. 6, DUTs are loaded on an A site (602) and a B site(604) of a handler. The handler transmits a test require signal SRQ(606) to a tester. After receiving the test require signal SRQ (608),the tester queries the handler whether the semiconductor devices in theA site and the B site are all loaded on a fullsite (610). The handlerreceives the fullsite query (612), selects either the A site or the Bsite (614), and connects a DUT from the selected site to the testersocket (616). The DUT state signal is transmitted from the selected site(618) and received by the tester (620). The tester tests the DUT (622and 624) and treats the test result (626). The handler receives the testresult (BIN) (628), sorts good devices and bad devices from the selectedsite and simultaneously selects another site (630). To test DUTs on thenewly selected site, the handler transmits the test require signal SRQto the tester and the subroutine (600) is repeated for the new site.

As explained so far, a test apparatus includes one handler connected toa tester, and either one test board divided into two or more sites, ortwo or more separate test boards. Since the test apparatus needs only asingle loading lane, a single tester, and a single sorter, and only thetest boards or test sites need to be multiple, the apparatus may beconveniently compact. Further, the apparatus can test DUTs in one siteor on one test board while simultaneously sorting DUTs according totheir test results in another site or on another test board. Thisenhances the efficiency of testing by reducing or eliminating testeridle time.

While the present invention has been described with reference to itspreferred embodiments, various alterations and modifications will occurto those skilled in the art. All such alterations and modifications maybe made within the scope and spirit of the appended claims.

1. A test apparatus for testing a plurality of semiconductor devicesloaded on one handler connected to a tester, the handler comprising: atleast first and second head boards on which semiconductor devices can beloaded for testing; and a test head to generate selection signalscorresponding to different head boards for sequential test cycles;wherein semiconductor devices loaded on the first head board are testedin response to one selection signal, and semiconductor devices loaded onthe second head board are tested in response to another selectionsignal; wherein the handler has the capability to sort, according to atest result obtained for the first head board, semiconductor devicesloaded on the first head board while semiconductor devices loaded on thesecond head board are selectively tested in response to the selectionsignal corresponding to the second head board.
 2. The test apparatus ofclaim 1, wherein the test head counts test cycles provided from thetester to generate different selection signals.
 3. A test apparatus fortesting a plurality of semiconductor devices loaded on one handlerconnected to a tester, the handler comprising: at least first and secondhead boards on which semiconductor devices can be loaded for testing;and a test head to generate selection signals corresponding to differenthead boards for sequential test cycles; wherein semiconductor devicesloaded on the first head board are tested in response to one selectionsignal, and semiconductor devices loaded on the second head board aretested in response to another selection signal; wherein the test headincludes a plurality of fuses, wherein different fuses are selectivelyshorted to a power supply voltage to selectively generate differentselection signals.
 4. The test apparatus of claim 3, wherein the handlerhas the capability to sort, according to a test result obtained for thefirst head board, semiconductor devices loaded on the first head boardwhile semiconductor devices loaded on the second head board areselectively tested in response to the selection signal corresponding tothe second head board.